Patent DE-102008003871-A1 (DE)
Title: Finishing thin metal sheet and/or products made of thin metal sheets later designed as semifinished sheet metal products using laser beam technology, by locally melting surface of products with laser beam up to in given sheet-metal depth
Inventor: WUNDERLICH GERD
IPC: C21D9/46
Filed: 2008-01-08
Abstract: The method for finishing thin metal sheet and/or products made of thin metal sheets later designed as semifinished sheet metal products using laser beam technology for surface-hardening, comprises locally melting the surface of the sheet metal products with a laser beam up to in a given sheet-metal depth, and introducing a filler material having a predetermined metal alloy into a melting region and melting a determined quantity of the metal alloy, so that the melted alloy metal material is contacted with the melted metal of the sheet metal products in a liquid state and then forms a melt. The method for finishing thin metal sheet and/or products made of thin metal sheets later designed as semifinished sheet metal products using laser beam technology for surface-hardening, comprises locally melting the surface of the sheet metal products with a laser beam up to in a given sheet-metal depth, introducing a filler material having a predetermined metal alloy into a melting region and melting a determined quantity of the metal alloy, so that the melted alloy metal material is contacted with the melted metal of the sheet metal products in a liquid state and then forms a melt, introducing a gas mixture into the melting region, so that the melted alloy metal material is contacted with the melted metal of the sheet metal products in the liquid state and then penetrates into the metal, and adjusting the influence of the laser beam on the region of the local melt and cooling the local melting region for hardening. The metal of the metal alloy is introduced as wire or powder in the region of the local melt. The process steps are successively carried out in a pre-determined short sequence and the laser beam is guided along the surface of the semi-finished sheet products. The metal sheet of the sheet metal products is made of soft, non-hardenable metal material. The alloy metal material is made of hardenable metal material. The metal material of the sheet metal products and the alloy metal material are made of steel. The metal material of the sheet metal products is made of non-hardenable light metal alloy material and the alloy metal material is made of hardenable light metal alloy material. The hard-cooling of the melting region is carried out by heat dissipation over the region of the sheet metal products using a cooling agent, which is supplied to the local melt region. The melted sheet-metal depth of the sheet metal products is determined by predetermining the residence time and the given output of the laser. The process is applied on different partial regions of the sheet metal products with different parameters such as melt depth, applied metal quantity, material of the alloy metal or hardness mode, where the partial regions have any shape and size. An independent claim is included for a semi-finished sheet metal product.